I also have the numb, useless hands in the morning or when I take a nap. I do have pinched nerves at wrists and elbows but tested negative for HNPP. I do have hereditary neuropathy. The pinched nerves are just a bonus.
I agree with Kitt that an EMG is a good idea, they usually do them together.
Does the numbness in your feet improve as the day goes on? My hands improve unless I overuse them but my feet and legs are permanently numb to thigh level.